AgSTAR’s New Anaerobic Digester Project Development Handbook

By Vanessa McKinney and Nick Elger of AgSTAR

For 26 years, the United States Environmental Protection Agency (US EPA) AgSTAR Program has been helping farmers and communities across the United States develop and implement anaerobic digestion (AD)/ biogas systems. These systems are critical to reduce methane emissions from manure management operations, while also providing other environmental and economic benefits. As a trusted partnership program, AgSTAR helps educate the public on best practices for designing, implementing and maintaining digester projects and brings together leading experts to discuss opportunities and challenges for advancing the biogas industry.

Anaerobic digestion systems are a useful technology for managing nutrients on livestock farms. When paired with nutrient recovery technologies, they can be effective at reducing nutrient runoff and improving soil health and local water quality.

AgSTAR’s newest resource, the soon-to-be-released Anaerobic Digester Project Development Handbook is a comprehensive compilation of the latest knowledge in the industry on best practices for AD/ biogas systems. The goal of the Handbook is to ensure long-term project success for AD biogas systems by providing background and a framework for AD project development.

The 3rd edition of the Handbook covers the basics of AD systems, including an overview of the biology and chemistry of the system, and addresses key questions to ask when developing and implementing an anaerobic digester project, including those related to complex business development aspects of projects. In addition, the Handbook includes information on AD/ biogas systems best management practices for nutrient management.

For whom is the handbook intended?

Although “Project Development” is in the title, this publication is not just for AD Project Developers. The Handbook has over 100 pages and 11 Chapters of content, with topics relevant to policy makers, financiers, and others interested in implementing AD/ biogas systems.

10 Keys to Digester Success

The 10 keys for digester success is a component of the Handbook that introduces the essentials for successful farm-based digester projects. This new resource was developed with feedback from experts in AD/ biogas system project development and offers helpful tips to consider for start-up, implementation, operation and continuous improvement of AD/biogas systems.

Work with an experienced team to initiate and implement the project. This will substantially increase the chance of project success. The complexity of these projects requires specialists.

3. Use a Sustainable Business Model

Not only should the project be cost-effective, it must meet the project’s financial goals including revenue and profit generation and return on investment. The economic factors include well-defined project costs, expenses, revenue or income, and liabilities, among many others. Personal goals for the project’s liquidity and profitability potential define the financial factors. The business model could consider involving partners, utilizing third party investments, or implementing other traditional ‘cooperative’ models.

4. Secure Suitable Feedstock Supply

Identify the quantity and quality of all suitable feedstocks and test feedstock initially for Total Solids (TS), volatile solids (VS) and Chemical Oxygen Demand (COD). Tests for biomethane potential (BMP) and Anaerobic Toxicity Assays (ATA) can be subsequently done. See AgSTAR Codigestion Guidelines for additional information.

5. Identify Appropriate Technology

No single AD technology can be used for all situations or all feedstocks. Rather, the AD technology must be chosen to match the project conditions and feedstock characteristics. There are alternatives such as composting, and aerobic technologies, which are also effective at converting organics.

6. Analyze Options for Biogas and Digestate Use

Consider market availability, capital and operating costs, and potential revenue to determine the most beneficial use for biogas. Determine the ability for digestate on-site use. Consider external markets for products such as bedding, compost, and fertilizer.

7. Develop Off-Take Agreements

Establish off-take agreements for energy and digestate products, including the prices and detailed specifications for all delivered materials.

8. Evaluate Added Benefits

Consider the added benefits of using AD, which may be difficult to quantify. These include climate, soil, water quality, sustainable food supply, community relations, and odor control.

9. Community Outreach

Community outreach and education is critical to obtain buy-in and approval from the community, including, but not limited to, regulatory approval and community and neighborhood approval where the project is located.

10. Plan for Operation and Maintenance

Good operation and maintenance practices are key for effective operation of AD/biogas systems. This includes continuous monitoring and management to ensure the biological processes and mechanical equipment are working properly. It is also important to consider whether current staff or a third party will be used to perform these functions.

A Connected Resource

In addition to details about AD/biogas system best practices, the Project Development Handbook contains links to dozens of additional resources from experienced professionals in the field to ensure that users have access to information beyond what is covered in the handbook.

Opinions expressed here do not necessarily reflect those of the Sustainable Phosphorus Alliance.

About the authors

AgSTAR is a collaborative partnership program sponsored by EPA and USDA that promotes the use of biogas recovery systems to reduce methane emissions from livestock waste. Vanessa McKinney is the Program Manager for EPA’s AgSTAR Program, where she works with U.S. livestock, biogas and government stakeholders to advance the deployment of digesters and biogas systems. Nick Elger is the Program Manager for the EPA AgSTAR Program and serves as the Agriculture Lead with the Global Methane Initiative. In his role as Program Manager for AgSTAR, Nick works with the U.S. livestock industry, state and federal agencies, and biogas industry stakeholders to advance the deployment of digesters and biogas systems. While supporting the Global Methane Initiative, Nick helps advance anaerobic digestion of organic feedstocks globally for methane mitigation and energy production.